Lock and alarm device

ABSTRACT

A bolt-type lock wherein the bolt is supported by a resilient member in the projected locking position such that the bolt can be deflected upon a predetermined opening force being applied against the closure members. Electrical contact means are positioned at the opening through which the bolt is projected and spaced from the bolt to be contacted by the bolt and close a circuit when said predetermined force is applied.

United States Patent [191 Hawkins LOCK AND ALARM DEVICE [75] Inventor:Paul Maddison Hawkins, Afton,

Minn.

. [73] Assignee: Minnesota Mining and Manufacturing Company, St. Paul,Minn;

[22] Filed: Apr. 23, 1971 [21] Appl. No.: 136,820

I [52] US. Cl..... ..340/274, 70/DIG. 40, ZOO/61.67

[51] Int. Cl. ..E05b 45/12 [58] Field of Search ..340/274; 70/DIG. 40;200/6168, 61.67, 61.93

[56] References Cited UNITED STATES PATENTS 3,444,546 5/1969 Hawkins..200/6l.67

[ 1 Apr. 10, 1973 11/ 1971 Hawkins ..340/274 7/1966 Bliven ..340/274Primary Examiner-Thomas B. Habecker Assistant ExaminerGlen R. Swann, lIlAttonuzy-Kinney, Alexander, Sell, Steldt & Delahunt [57] ABSTRACT Abolt-type lock wherein the bolt is supported by a resilient member inthe projected locking position such that the bolt can be deflected upona predetermined opening force being applied against the closure members.Electrical contact means are positioned at the opening through which thebolt is projected and spaced from the bolt to be contacted by the boltand close a circuit when said predetermined force is applied.

7 Claims, 7 Drawing Figures PATENTEDMR 1 0 15 3.727. 210

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LOCK AND ALARM DEVICE BACKGROUND OF THE INVENTION The present inventionrelates to locks including an alarm system to be actuated when anattempt is made to force the lock.

Combinations of locks and alarms are well known in the art and variousconstructions of locks have been developed which actuate an alarm upon apredetermined force being applied against the lock in an attempt toforce open a closure. The prior art includes combinations where the boltmember is supported in a housing in a manner such that upon apredetermined force being applied against a projected bolt the entirehousing will be pivoted to actuate a switch setting off an electricallyactuated alarm or other signal. Other forms include means forresiliently supporting the bolt within a lock casing such that when apredetermined force is applied against the bolt the bolt is fulcrumed atthe opening in the lock casing to trip a switch or catch to actuate analarm. These devices generally incorporate spring-mounting devices whichtend to maintain the bolt in a normal centered position in the lockcasing as it is moved between projected and retracted positions.

Other examples of prior art include electrical contacts positioned in akeeper which is mounted on one of the closure members for receiving thebolt. A predetermined force being applied against the closure membersupporting the bolt causes the bolt to move relative to the keeper andengage the electrical contact, thus actuating an alarm.

The earlier constructions using a resilient mounting for the bolt or thecasing have used an increasing number of parts and therefore theassembly operation is increased. Further, the manufacture of locks ofthat type utilizing springs permit the alarm to be actuated undervarying amounts of force depending upon the precision with which thelocks are assembled and the springs are set. Other vagaries inmanufacture change the operation of the alarm system due to frictionbetween the cooperating movable parts. A lock and alarm system whereinthe alarm is actuated by movement of the bolt in the keeper requiresincreased installation costs when both the door and the jamb requiremore reconstruction than is normal for installation of other forms oflocks and alarms.

A lock and alarm structure according to the present invention affords asimpler construction and greater uniformity between locks. Uniformity ofoperation between lock structures according to the present invention isnot dependent on the assembly operation of the lock. The new lockstructure also affords greater versatility in its use as the structurepermits its use with a greater variety of closure members without achange in the structural elements.

SUMMARY OF .THE INVENTION The lock and alarm device of the presentinvention utilizes a conductive bolt which is supported by a resilientsupportqmember or rod cantilever mounted within. the housing. Theresilient rod may be movable relative to the support to place the boltin the retracted and projected positions or the bolt may be movable upona fixed cantilever mounted resilient rod. The bolt projects through anopening in the lock casing which is somewhat larger than the dimensionsof the bolt and when a predetermined force is applied against theclosure members with the bolt in a projected position the resilient rodpermits movement of the bolt under the force of an attempted opening tomake electrical contact with contact means disposed at the opening toclose a circuit. A suitable alarm circuit is employed to generate asignal and this alarm circuit once closed would remain closed as by anSCR such that upon release of the force against the closure members anda return of the bolt to its normal position the signal would becontinued until the circuit is subsequently opened by a separate switch.

DESCRIPTION OF THE DRAWINGS The present invention will be more fullydescribed in the following detailed description which relates to theaccompanying drawing wherein:

FIG. 1 is an elevational view of a lock and alarm device, constructedaccording to the present invention, mounted on a closure member whichcooperates with an additional closure member;

FIG. 2 is a bottom view of the device as seen along the lines 2--2 ofFIG. 1;

FIG. 3 is a view of the device with the casing in section and some ofthe parts of the lock in section to show interior parts, and is takengenerally along the lines 3-- 3 of FIG. 2;

FIG. 4 is a fragmentary sectional view showing a second embodiment of alock and alarm device constructed according to the present invention;

FIG. 5 is a fragmentary sectional view of the device of FIG. 4;

FIG. 6 is a sectional view of a further embodiment of a lock and alarmdevice constructed according to the present invention; and

FIG. 7 is a sectional view of the device of FIG. 6 taken along the lines7-7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to theaccompanying drawing there is shown in FIG. 1 a lock and alarm structure10 mounted on a closure member 11 in a position to be adjacent a secondclosure member 12 which may be a door jamb, a second door slidablerelative to the first closure member 11, or the members 11 and 12 may berelatively movable window frames or a window frame and sash.

The lock structure 10 comprises a bolt 14 which is movable from aretracted position to a projected position as shown in FIG. 1 and isreceived within a boltreceiving housing or keeper 15 on the otherclosure member 12. The casing for the lock structure 10 is formed with agrill 16 positioned over a speaker within the lock structure and a knob17 is used for moving the bolt 14 from a retracted to a projectedposition to lock the closure members. As seen in FIG. 3 with the frontplate of the casing 13 removed the lock structure comprises a supportmember including a base plate 18 which is mounted on the closure memberand a support block 19, which is formed by two mating identical halvessecured to the base plate by fasteners 20. The halves of the supportblock 19 are formed to define a central cavity or bore 21 extendingaxially through the support block 19. Positioned in the bore 21 at oneend means which may be engaged by the bolt when the same is forced (asshown in broken lines) transversely of its axis toward the ring 25 inthe opening 24. The ring 25 is connected to an alarm circuit by means ofa conductor 26. The annular contact 25 thus forms one contact in thecircuit. A second conductor 29 from the alarm circuit is connected tothe conductive sleeve 22 and contact with the resilient rod 23 isassured by the ,use of a detent comprising a ball 27 and spring 28. Thespring 28 urges the ball 27 into contact with the resilientrod 23. Theball 27 engages a groove in the resilient rod 23 to maintain the same inits projected position to avoid displacement of the bolt from itsprojected position. Alarm circuit is closed by the bolt 14 engaging thering 25 upon a predetermined force being applied against the bolt 14 byrelative movement of the closures to flex the rod 23 along its lengthbetween the bolt and the sleeve 22 where it is supported in a cantilevermanner.

The conductors 26 and 29 are connected to the alarm circuit which may beany suitable alarm circuit which will generate a predetermined signal.As-illustrated the lock and alarm device has a self-contained circuitand a speaker 34 will produce an audible signal. The electrical circuithas an SCR and is adapted to maintain the generation of the audiblesignal until a second set of contacts 31 are coupled by operation of aswitch blade 32 formed with a shoulder 33 to engage the contacts. Theswitch blade 32 is slidable in a slot 35 in the support block 19 betweenan operative and inoperative position. The switch blade 32 extendsoutward of the casing 13 for the lock and alarm device to be actuated.Power to the enclosed circuit in the lock alarm device 10 illustrated isprovided by a power pack'36 comprising dry cell batteries. Theelectrical alarm circuit is mounted on a circuit board 30 disposedwithin the casing 13 below the speaker 34 and is supported by themounting plate 18. i

The bolt 14 of the lock alarm structure 10 is machined of brass and ismachined to retain a pointed end 37 which may be used on installation ofthe lock and alarm device 10 on the closing membersto fix the positionfor the bolt-receiving member on the other closure member 12.

The lockand alarm deviceas shown in FIGS. 4 and 5 corresponds generallyto that shown in FIGS. 1 through 3, however this embodiment is providedwith a keyoperated lock to maintain the bolt 14 in theprojectedposition. This embodiment has particular utility for use with closuremembers having glass or breakable panels to avoid the unlocking of thelock; As seen in FIGS. 4 and5 the bolt 14 is supported for movement in asupport block 39 provided with a bore 40. The bore 40 is enlarged at oneend providing an enlarged cavity 41 to slidably receive a lock cylinder44 of a pin tumbler lock in which is mounted a rotatable plug 45 formedwith a keyway. A resilient rod 42 is fixed to the bolt 14 and is securedto one end of the rotatable plug 45. The cylinder 44 is maintained inthe cavity 41 by a screw 46 which is threadably connected to thecylinder and is guided in a slot 47 formed in the mounting block 39 topermit reciprocation of the cylinder. A spring biased projection 48extends from the lock cylinder 44 to engage a recess 49 when the lockcylinder 44 is moved inwardly in the cavity 41 to the solid lineposition shown in FIG. 4. The projection 48 retains the lock cylinder inthis position until a suitable key 62 is inserted in the keyway in theplug 45 and rotated to release the projection from the recess. Thecylinder 44 is moved from the inserted position outwardly of the cavity41 under the bias of'compression springs 50 and 51 which extend from thelock cylinder 44 parallel to the axis and into engagement with aconductive washer 52 disposed at the inner end of the cavity 41.

In this embodiment the electrical contact means comprises a conductor 56joined to the washer 52 and a conductor 58 which is joined to an annularconductive ring 59 surrounding the opening in the support block 39through which the bolt 14 projects.

Referring now to FIGS. 6 and 7 there is disclosed a lock and alarmstructure mounted on a closure member 71 and having a conductive bolt 72projecting into a bolt receiving member 73 supported by a second closuremember 74. The lock structure comprises a casing 75, a support plate'77having an upturned flange 78 formed with an opening 79, a support memberfor the bolt 72, an electric circuit on a printed circuit board 80, apower pack 81 comprising dry cell batteries, and a speaker 82. Thesupport member for the bolt 72 comprises a support block 85 which isfixed to the support plate 77 and a pair of parallel resilient rods 86and 87, formed of spring. steel. The rods 86 and 87 are fixed at one endto the support block 85 and extend therefrom toward the opening 79. Therods 86 and 87 are received within bores 89 and 90 formed in the bolt72. The rods 86 and 87 support the bolt 72 forsliding movement betweenthe retracted position within the casing 75 to a projected positionoutward of the opening 79 to engage the bolt receiving member 73. In itsprojected position the bolt 72 securely locks the enclosure members 71and 74.

The bolt 72 is moved between its retracted broken line position to itsprojected solid line position, as shown in FIG. 6, by rotation of asleeve 94 supported by the support block 85. The sleeve 94 is fixed to aradial arm 95 which is coupled to a link 96 which link 96 is pivotallyconnected to the bolt 72. Rotation of the sleeve 94 through an angle of90 degrees by a thumb turn 97 or by the rotatable plug 98 of a pintumbler lock cylinder 99 will cause reciprocation of the bolt 72 on therods 86 and 87. A spring 100 assists the arm 95 and link 96 to positionthe bolt.

The electrical circuit is energized when a force is applied transverseto the axis of the rods 86 and 87 against a closure member to move, thebolt 72 toward the closure 71. The circuit is energized by joiningcontact means placed at the opening 79. As illustrated the contact meanscomprises a pair of spaced conductive strips 102 and 103 supported on abacking 104. The

gaged and joined by contact with the bolt. Similar contacts, not shown,may be positioned on the opposite side of the opening from the strips102 and 103 to close the circuit when the lock and alarm structure 70 isused with outswinging closures. The circuit can be opened to stop thealarm by closing a further pair of contacts 108. The contactsl08 can beclosed by connecting them through a pivoted conductive bar 109 or byforcing them together by reciprocating the bar 109. The bar 109 issupported by the support block 85.

The operation of the locking bolt in the devices of the presentinvention is very similar to the operation of existing dead bolts. Theopening through which the bolt projects however has dimensions greaterthan that of the bolt so as not to confine the bolt against movementtransverse to its axis. The resilient'rod supporting the bolt and thespacing between the bolt and the contact means at the opening determinethe force necessary to cause an alarm to be actuated.

Having thus described the present invention and several embodiments oflock and alarm devices constructed according to the invention, it isunderstood that structural modifications can be made in said deviceswithout departing from the spirit or scope of the invention.

What is claimed is:

l. A lock apparatus for use with cooperating closure members to effectan alarm upon limited relative movement of said closure members, saidapparatus comprismg a bolt member formed to join said closure memberswhen in a projected position, said bolt being formed to affordelectrical conduction,

asupport member adapted to be secured to one of said closure members,said support member having an opening through which said bolt may bemoved from a retracted position to a projected position,

resilient support means for supporting said bolt for movement along itsaxis from said retracted to said projected position through said openingand for movement transverse to its axis, and

electrical contact means positioned adjacent the opening in a positionfor contact by said bolt such 10 jected position and affording acantilever mount for said rod when said bolt is in said projectedposition.

3. A lock apparatus according to claim 1 wherein said resilient supportmeans comprises a fixed resilient rod and a fixed support for one end ofsaid rod to project the same toward said opening, and wherein said boltis formed with an opening to slidably receive said rod to affordmovement of said bolt on said rod between a projected position and aretracted position, and wherein said apparatus comprises means forsliding said bolt on said fixed rod between said projected and retractedpositions. I I

. A lock apparatus according to claim 2 wherein said contact meanscomprises an electrical contact connected to said resilient supportmeans and a conductive member positioned at said opening for contact bysaid bolt when a predetermined force is applied against said bolt toflex said rod sufficiently to move said bolt into contact with saidconductive member.

5. A lock apparatus according to claim 3 wherein said contact meanscomprises a pair of spaced contact members positioned at the edge ofsaid opening for engagement by said bolt to close a circuit when saidfixed rod is flexed sufficiently to move said bolt against said spacedcontact members.

6. A lock apparatus according to claim 2 wherein a key operated lockcylinder is secured to the end of said rod opposite said bolt, and saidsupport means includes a cavity for receiving said cylinder andretaining the same upon sliding movement of said bolt to said projectedposition.

7. A lock apparatus according to claim 1 wherein said support membersupports a speaker to produce an audible signal upon contact of saidbolt with said con-- tact means.

1. A lock apparatus for use with cooperating closure members to effectan alarm upon limited relative movement of said closure members, saidapparatus comprising a bolt member formed to join said closure memberswhen in a projected position, said bolt being formed to affordelectrical conduction, a support member adapted to be secured to one ofsaid closure members, said support member having an opening throughwhich said bolt may be moved from a retracted position to a projectedposition, resilient support means for supporting said bolt for movementalong its axis from said retracted to said projected pOsition throughsaid opening and for movement transverse to its axis, and electricalcontact means positioned adjacent the opening in a position for contactby said bolt such that movement of said bolt in said opening in adirection transverse to its axis under a predetermined force will affordcontact with said contact means to close a circuit.
 2. A lock apparatusaccording to claim 1 wherein said resilient support means comprises aresilient rod fixed to said bolt, and said apparatus comprises supportmeans for said rod affording sliding movement of said rod to move saidbolt between said retracted and projected position and affording acantilever mount for said rod when said bolt is in said projectedposition.
 3. A lock apparatus according to claim 1 wherein saidresilient support means comprises a fixed resilient rod and a fixedsupport for one end of said rod to project the same toward said opening,and wherein said bolt is formed with an opening to slidably receive saidrod to afford movement of said bolt on said rod between a projectedposition and a retracted position, and wherein said apparatus comprisesmeans for sliding said bolt on said fixed rod between said projected andretracted positions.
 4. A lock apparatus according to claim 2 whereinsaid contact means comprises an electrical contact connected to saidresilient support means and a conductive member positioned at saidopening for contact by said bolt when a predetermined force is appliedagainst said bolt to flex said rod sufficiently to move said bolt intocontact with said conductive member.
 5. A lock apparatus according toclaim 3 wherein said contact means comprises a pair of spaced contactmembers positioned at the edge of said opening for engagement by saidbolt to close a circuit when said fixed rod is flexed sufficiently tomove said bolt against said spaced contact members.
 6. A lock apparatusaccording to claim 2 wherein a key operated lock cylinder is secured tothe end of said rod opposite said bolt, and said support means includesa cavity for receiving said cylinder and retaining the same upon slidingmovement of said bolt to said projected position.
 7. A lock apparatusaccording to claim 1 wherein said support member supports a speaker toproduce an audible signal upon contact of said bolt with said contactmeans.